In the Alife-Matese area, the existence on the western extremity of Monte Nicola of pre-Roman fortified walling has been known for some time. Tracts of this polygonal masonry (of the so-called “I maniera”) are visible at different heights, running lengthways on the mountain slope facing the modern town. The presence of these walls was confirmed and brought to light by D. Caiazza and S. P. Oakely. Thanks to an examination of aerial photographs undertaken by Nicola Lombardi and the subsequent excavation, a monumental and spectacular late Republican sanctuary complex was uncovered. At its centre was a temple with a theatre, built on different levels, inside an area delimited by the Samnite walls, set in a landscape of great natural beauty. The temple stands on the highest point, at the centre of a square artificial terrace (700 m2), delimited on all sides by imposing substructure walls. The temple was in the Tuscan style, with a triple cella. In the south-eastern corner an _opus signinum_ tank/pool collected rainwater from the roof which was then channelled into a cistern. Pottery fragments and several walls abutting or overlying the originals attest a phase of medieval reoccupation, which may have continued into the later medieval period. What remained of the partially explored theatre below was the semicircular cavea (2500 m2), cut into the natural slope and delimited by _opus incertum_ walls in local limestone and part of the stage building. On the south side were four imposing semicircular towers which acted as buttresses for the building and created a view of a monumental architectural façade from the valley below.

In June 2005 excavations continued on the theatre-temple complex on Monte San Nicola in the municipality of Pietravairano. A study of the building techniques ( _opus incertum_ with quoining of small limestone blocks) and of the small amount of residual pottery, dated the monument to within the first quarter of the 1st century B.C. The excavation of specifically placed trenches undertaken by the University of Lecce defined the stratigraphic sequence and architectural organization of the complex, with particular reference to the link between the cavea and the temple terrace. A trench placed in correspondence with the eastern sector of the cavea confirmed the absence of structures outside the _analemma_ wall, highlighting the presence of the radial stairways linking the media and _summa cavea_, as well as the diazoma between these two sectors. The research was completed by surface surveys carried out along the crest of the mount. In an area east of the emerging structures a survey identified a tile collapse and a curved wall made of parallelepiped blocks belonging to a small building, probably with an apse, that may be identified with the chapel of the already known medieval settlement.

Work continued between 10th April and 31st May 2006 on the excavation and restoration of the site at Pietravairano. A large sector of the cavea was brought to light, partly cut into the limestone bedrock and completed with a staircase built in _°opus caementicium_, leading up to the level of a small orchestra. The clearing of the terrain in the areas to the east and north of the temple terracing revealed numerous fragments of palmetted cyma and drips in the form of lion heads, coherent with a roofing system datable to the second half of the 2nd century B.C. Another trench was dug to investigate the relationship between the cavea and the theatre’s western _analemma_ wall. Lastly, surface survey and mapping continued across the entire area.

This campaign, May 2007 to February 2008, saw the complete exposure of the temple building, the terracing on which it stands and part of the _cavea_ of the theatre below. The investigations definitively proved that the structures were part of a single complex, conceived as such from the first construction phases. Important evidence regarding the temple’s architectural decoration, the abandonment of the sanctuary, the subsequent re-occupation phases of in the area was documented, and the first epigraphic evidence from the sanctuary was found. The excavation of the upper terrace and the temple clarified its plan and typological characteristics. About 11.54 m long and 13.62 m wide, it was a Tuscan type temple with a triple _cella_ and a tetrastyle façade (with tile-built columns), built with a certain adhesion to Vitruvian architectural canons. Thirteen burials were uncovered in the excavation area, mainly situated up against or close to the temple’s south wall. Either without grave goods or with extremely small assemblages, the tombs document the abandonment and defunctionalisation of the theatre-temple complex, as well as the subsequent re-occupation of the site. Tomb 7, an “a cappucina” type burial, produced a bronze _aes_ mentioning the fourth consulship and the fifteenth _tribunicia_ _potestas_ of Antoninus Pius (151-152 A.D.). Therefore, the sanctuary complex would seem to have lost its original function perhaps as early as the mid 2nd century A.D. However, occupation of the site continued in the medieval period. This was attested by the materials from three other burials, such as a bronze “basket” earring with a glass pendent from tomb 8, and, above all, the bronze open ring fibula, with volute terminals, found in tomb 13, similar to types widespread in early medieval contexts in Campania and southern Italy. Further evidence was provided by the later pottery fragments found close to the central _cella_ of the temple, and the remains of a chapel built on what remains of the ancient _skenè_, dedicated, according to local tradition, to San Nicola. As regards the theatre, the excavations uncovered the tiers of the upper and middle parts of the _cavea_ hemicycle (radius c. 21.5 m), built exploiting the natural slope, and delimited by containing walls (_analèmmata_) in local limestone _opus_ _incertum_. A wide passageway (_diàzoma_) separated the upper part of the _cavea_ from the middle part, while three steps divided the tiers visible at present into four wedges. The tiers are relatively well-preserved, although the actual seat surfaces have not survived. The excavation of this sector of the monumental complex produced fragments of the architectural decoration from the temple above and two examples of a Latin tile stamp, attesting the production activity of a workshop belonging to the _gens_ of the _Aufidii_.

In September 2012, excavations carried out by the Università del Salento reopened on the sanctuary complex of Monte San Nicola. The excavations (19th September – 23rd November) opened a new area (Trench E) in correspondence with the eastern sector of the _cavea_, between the ninth tier of the _media_ _cavea_ (the last uncovered in the 2007-2008 campaign) and the present ground level, above the original floor level of the orchestra, with a difference in height (north-south) of c. 1.80 m. The excavations identified the point of passage between the _media_ and _ima_ _cavea_, and partially uncovered the tiers in the latter. The initial investigations also checked the stratigraphic sequence of the _cavea_, clarifying the dimensions and composition of the various layers. Of note layer US 23 which contained a high concentration of limestone chips, pottery fragments (generally cooking wares, but also black glaze cups and very occasional sigillata italic), parts of lamps, tegulae, imbrices, as well as a substantial quantity of architectural fragments from the temple decoration (terracotta _syme_ decorated in relief with palmettes and lion’s head spouts), small blocks of grey tufa and fragments of white and red plaster. After the opening of trench E, the excavations concentrated on the area of the _media_ _cavea_ and in particular, starting from the north at the height of the ninth tier. The excavation went down at least 1.20 m from the initial ground level, uncovering two more tiers of the _media_ _ cavea_, with the related lateral and central steps (_klimakes_). Lying underneath these tiers was another wall, slightly higher than the preceding ones, that seemed to delimit a transverse passageway, a sort of _diàzoma_ dividing the lowest tiers of the _ima_ from those of the _media_ _cavea_ and was accessed from the orchestra via a short stretch of the central stairway, while the lateral stairways stopped precisely in correspondence with this passage. The final phases of the 2012 season involved experimental interventions to restore the _cavea_ tiers. The interventions are reversible, aimed at this stage to test the actual efficiency in terms of protection and resistance of the adopted solutions and ability to preserve the tiers from the incessant action of atmospheric agents, in particular rainwater runoff and the seasonal cycle of freezing and unfreezing.

The work, carried out by Salento University, aimed to complete the excavation of the theatre-temple complex. In the theatre, largely excavated in 2007-2008, the excavation of the pronaos was deepened, at the centre of which an "a cappucina" burial, without grave goods, was found (n.14). Another tomb (n. 15), of the same type and also without grave goods, was found in the south-western sector of the terrace. It contained a child that still had its milk teeth. The lack of grave goods in both burials means they cannot be dated based on the archaeological evidence. The recent investigations also involved the entire theatre building. Sixteen tiers of the _cavea_ were brought to light, divided horizontally in three sectors by two wide passageways, while the presence of three flights of steps subdivided the _cavea_ itself into four parts or wedges. The orchestra, still to be completed, has so far been investigated through limited _sondages_, which however revealed the original floor surface, made up of compact mortar with small limestone and tile inclusions. Large sections of the same floor were also present along the _aditus_, the points of access to the theatre that sloped down from the exterior towards the orchestra level. The _proscaenium_ was completely exposed and in the central sector an opening 0.80 m wide provided entry to the scenery pit that was originally covered by the wooden _pulpitum_. The theatre entrances were monumentalised with vaulted passageways of which traces of the walls remain at foundation level abutting the containing walls of the _cavea_. The facade of the _proscaenium_ must have been decorated with terracotta pilasters, attested by several traces, while a central opening provided access to the scenery pit (_hyposcaenium_), the same length as the _scenae_ _frons_, covered by wooden planks (_pulpitum_) of which all traces are lost. The _scenae_ _frons_ was supported to the rear by semicircular buttresses. In addition to the imposing substructures, short sections of the walls are standing, evidence of its ancient glory. However, we have no evidence for the reconstruction of the form and decoration of the front wall of the stage structure. Probably covered by a flat roof, this structure was delimited to the south by one of the highest and most imposing walls within the sanctuary complex, certainly the longest, which must have been clearly visible from the valley below.